Security researchers from Palo Alto Networks detected a large-scale cryptocurrency mining operation than last for more than 4 months. Researchers believe it impacted more than 30 million people worldwide. Attackers used malware for Mining Monero using high-performance XMRig.
Threat actors used VBS file and various URL Shortening methods to install and run the XMRig payload. The campaign impacts worldwide and heavily over Southeast Asia, Northern Africa, and South America.
Palo Alto researchers observed more than 250 unique Microsoft Windows PE files in this Monero cryptocurrency mining campaign. Over half of these samples were downloaded from the 4sync online cloud storage provider.
Hackers used Adfly URLs to target individuals and if clicked the provided link, were redirected, and found themselves downloading this cryptocurrency malware onto their computers. Based on the telemetry data analysis via bitly at least 15 million affected worldwide.
Miner Installation – Cryptocurrency Mining
Initially, it drops a VBScript(VBS) with LNK file, then with BITSAdmin service it downloads and executes the remote VBS files then the final payload is msvc.exe. VBS file determines the system is running a 32-bit or 64-bit operating system.
After October 20, 2017, attackers started using HTTP redirection service and removed BITSAdmin service for downloads. And they continued to use SFX files to download and deploy their malware.
Starting from November attackers again changed their methods, they stopped using SFX files, instead transitioned to using an executable file compiled by Microsoft.
Researchers said dropper malware is typically dropped with a filename of either ‘msvc.exe’ or ‘mingc.exe’. Additionally, a unique PDB string is found in a number of these samples, which always use the same username for the user that compiled it.
Again in late December attackers changed the dropper, they moved away from .NET and the VBS dropper compiled with Borland Delphi and the droppers are placed in the victim’s startup folder for persistence.
The campaign impacts worldwide and heavily over Southeast Asia, Northern Africa, and South America.The most commonly hit countries and their download counts are as follows.
Thailand – 3,545,437 Vietnam – 1,830,065 Egypt – 1,132,863 Indonesia – 988,163 Turkey – 665,058 Peru – 646,985 Algeria – 614,870 Brazil – 550,053 Philippines – 406,294 Venezuela – 400,661
Cryptocurrency mining is in the raise starting from last year, more than 500 million computers are mining cryptoCurrency in their browsers without the user’s knowledge.
we suggest our users be extra cautious while visiting sites on the internet from now on. And if you like some website or a blog and want to support them, you may allow them to mine crypto-currency using your computer’s energy.